Artemis II launch countdown begins as NASA takes historic step towards returning to the moon TONIGHT: Live updates

Astronauts Reid Wiseman, Victor Glover, Christina Koch and Jeremy Hansen have boarded the Orion spacecraft and are hours away from rocketing into space on the Artemis II mission.

The 32-story Space Launch System rocket is set to blast off this evening with a two-hour launch window beginning at 6.24pm ET.

They will hurtle several thousand miles beyond the moon, hang a U-turn and then come straight back over a 10-day period.

The astronauts are sealed inside the Orion capsule, entering the final stage before humanity’s first trip toward the moon in more than half a century.

After reaching the launch pad, the crew took an elevator high above the ground and signed their names inside the historic ‘white room,’ the last stop before boarding the spacecraft.

With helmets locked and suits adjusted, they climbed into the tight capsule, roughly the size of a small camper van, where they could remain for 10 days if the mission launches on schedule.

Satellite images show NASA's Artemis II Space Launch System (SLS) rocket and Orion spacecraft at Launch Pad 39B at the Kennedy Space Center in Cape Canaveral, Florida, ahead of its launch today.

Donald Trump celebrated the Artemis II launch, using it as an opportunity to tout US dominance in space.

'Tonight at 6.24pm EST, for the first time in over 50 YEARS, America is going back to the Moon! Artemis II, among the most powerful rockets ever built, is launching our Brave Astronauts farther into Deep Space than any human has EVER gone,' he wrote on Truth Social.

'We are WINNING, in Space, on Earth, and everywhere in between - Economically, Militarily, and now, BEYOND THE STARS. Nobody comes close! America doesn’t just compete, we DOMINATE, and the whole World is watching.

'God bless our incredible Astronauts, God bless NASA, and God bless the Greatest Nation ever to exist, the United States of America!'

NASA is hours away from its first crewed mission around the moon in 53 years, leaving one astronaut to have a heartbreaking conversation with his daughters.

Reid Wiseman, commander of Artemis II, is set to launch this afternoon alongside NASA's Victor Glover and Christina Koch and Canadian Space Agency astronaut Jeremy Hansen for a 10-day lunar flyby.

Before heading to NASA's Kennedy Space Center in Florida, Wiseman, 50, took his daughters, Ellie and Katherine, for a walk to prepare them for the event of his death during the mission.

NASA Astronaut tells daughters death plans before Artemis II mission

A NASA astronaut set to launch to the moon this week was forced to have a heartbreaking conversation with his two daughters ahead of the Artemis II mission.

Scientists have raised safety concerns about the Orion capsule's heat shield ahead of NASA's long–awaited Artemis II mission.

Set to launch as early as 1 April, the mission will see four astronauts – Reid Wiseman, Victor Glover, Christina Koch and Jeremy Hansen – blast off on a 10–day mission to the moon.

During the mission, the astronauts will travel around our lunar satellite on board Orion – a cramped capsule measuring just 11ft x 16.5ft.

Now, Ed Macaulay, a lecturer in Physics and Data Science at Queen Mary University of London, has voiced his fears about Orion's heat shield, which bears the brunt of the searing heat during re–entry through Earth's atmosphere.

Is NASA's Artemis II safe? Scientists raise concerns about heat shield

Ed Macaulay, a lecturer in Physics and Data Science at Queen Mary University of London, has voiced his fears about Orion's heat shield, which bears the brunt of the searing heat during re-entry.